This program project is concerned with the localization and physiological role of a number of centrally acting peptides which are either of central or peripheral origin. The specific peptides of interest are thyrotropin releasing hormone (TRH), luteinizing hormone-releasing hormone (LRF), somatostatin, vasopressin, ACTH, peptides derived from pars intermedia/nervosa and an antigonadotropic peptide of pineal gland origin. Techniques of localization include radio-receptor assay, bioassay, radioimmunoassay and immunocytochemistry. Antibodies to a number of these peptides will be generated by selection of monoclonal lines of hybridized mouse myeloma cells.